In short, modifications for games are "mods." Not "MODs." And, for the record, it's "id" - not "ID" or "iD" (the most ridiculous of them all, perhaps).

Uh oh, I hear chants of "VALVe."

I dunno when it was made official but it is according to dictionary.com. BTW, I believe someone has brought up this subject on the forum before...

MOD

vt.,n. [very common] 1. Short for `modify' or`modification'. Very commonly used -- in fact the full terms areconsidered markers that one is being formal. The plural `mods' isused esp. with reference to bug fixes or minor design changes inhardware or software, most esp. with respect to patch sets or adiff. 2. Short for modulo but used _only_ for its techspeaksense.